The physical nature of seeds, and particularly whole cereal grain kernels, involves both polar and non-polar areas in which an imbalance of vector forces produce a metastable condition such that the net forces attempt to reach maximum stability. Such a state is the result of the complex component polymers and the interrlationship of those polymers which comprise the various seed tissues. Because of its presence in large proportion, the starch-protein-hemicellulose matrix of the endosperm is highly relevant to the metastable state of the seed. Comprised mostly of starch granules, the filamentous and globular protein and, to a lesser extent the cellulose polymers, sharply inhibit such polymeric availability.
Virtually every single use for such seeds must, of necessity, attempt to cope with the physical nature involving the metastable conditions therein. As a result, practically all processes pertinent to the utilization of grain seeds involve physical reduction of the seed as the only possibility for seed tissue availability. For animal feeding, comminution in the form of grinding, rolling, crimping, and the like, is common, a fundamental function of which is to provide smaller particles for mixing with other mixed feed constituents, for stability of such mixes, and tissue availability.
For whole seed uses, other than food or feed, coping with the inhibiting seed tissue interrelationships is generally more serious. Fashioning products always involves comminution in the simplest of concepts, and usually crude tissue fractionation is involved as is the case for the dry milling of wheat, corn and grain sorghum. Where complete tissue or polymer fractionation is mandatory, such as in the wet milling of corn, the seeds are processed in whole grain form preparatory to subsequent hydraulic and gravitational separations.
Steeping processes, such as in corn wet milling, involve whole grain treatment by aqueous chemical systems. The highly polar molecules of water, for example, may permeate the seed pericarp with subsequent adsorption in the internal polar regions of the seed. Although the rate of adsorption is relatively rapid upon initial water exposure, the rate diminishes rapidly until saturation is reached, the saturation point being dependent upon the extent and specific variation of structuralization of the individual seed, but whose saturation is relatively low in any case.
Limitations on water imbibition are further complicated by the variable, but sharply limited, ability of chemicals to penetrate the seed endosperm. At best, steepants in low concentrations, and including oxidizing, reducing, hydrolytic and swelling agents, vary in penetration due to nonuniform adsorption and swelling. High concentrations of chemicals in aqueous solutions exhibit even less efficacy due to rapid swelling which precludes further chemical adsorption. Furthermore, total chemical adsorption, regardless of non-uniformity and other factors, is further restricted by the relatively low amount of water which may be adsorbed. Sodium chloride, for example, may be adsorbed by the whole kernel to a modest extent, the maximum of which may be sharply defined, but that amount is adsorbed by the pericarp only and may be readily desorbed and removed by simple aqueous elutriation. Urea, on the other hand, may be adsorbed by contact with an aqueous solution, but the problems encountered obviate any possible economic processing. For example, mixing whole cereal kernels with a concentrated urea solution containing 10 percent urea (based on the grain dry weight), results in an extremely sticky mixture. Even with frequent agitation the condition of the mixture, not unlike a mixture of grain and very heavy molasses, persists for long periods of time, rendering the prospect for commercial utilization completely unacceptable.
A well known function of urea is the softening of cellulose, a major component in seed pericarps, and is used extensively in the paper industry for that purpose. It is apparent that softening of seed pericarps is at least partially accountable for the untenable handling characteristics caused by the urea solution mixed with the whole seeds.
Prospective solvents, other then water, have practically no value whatever because of the difficulty in subsequent removal of those lacking in feed or food utility and because of lack of solubility of solutes in those solvents which might be acceptable. Nonpolar compounds may or may not be adsorbed by whole seeds, depending upon molecular size and other characteristics peculiar to molecular configurations. Fats, oils and greases, regardless of source, are not adsorbed in significant quantities, it at all, and, if adsorbed, tend to migrate toward nonpolar areas of the seed tissues.
From the aforegoing it can be seen that the list of possible solvents in present processes can be narrowed, for all practical purposes, to only one, water, and selected chemicals limited to those which are soluble in water. Utility is further restricted by the numerous limitations set forth above. Completely eliminated from prospective use are an enormous number of solids which otherwise would be very useful as an integral part of the plant seed. With that apparently overwhelming limitation removed, a host of new processes, together with substantially improved present processes, would become available for markedly improved utilization of plant seeds, and particularly for cereal grains.
Total worldwide grain utilization is prodigious by any standard. In economically developed countries the animal feed manufacturing and feed grain trading industries are very large and are totally related. Additionally, corporate manufacturers of various chemical additives such as minerals, drugs, vitamins, hormones, and the like, contribute significantly to the total size of the industry. Moreover, the industry is growing, with indications that it will continue to grow, perhaps at an accelerated rate. Further contribution to industry growth has been from increased efficiencies resulting from greatly expanded feeding operations and increased delineation of nutrition requirements. Attendant to increased efficiencies have been new methods with new problems, presenting opportunities for solutions.
Feed grains form the base for all high energy animal rations by providing the only universally desirable and economic source of energy. Most of the energy is furnished by the starch, comprising about 70 percent of the "as is" moisture grain, and, to a lesser extent, from the protein, fat and fiber. However, cereal grains, like other individual feed ingredients, virtually never satisfy all the nutritive requirements for any animal type, which is further complicated by animal age and purpose (meat, eggs, milk, reproduction, and the like). Nonetheless, it is believed that cereal grains satisfy more of the requirements than any other single ingredient type. In the present state of the art, there is no known method which is satisfactory for incorporation of additives into whole cereal kernels.
It is well known that the cereal grains contain vitamins, minerals and other necessary nutrients, but those are usually present in small quantities, unsatisfactory proportions for various purposes, and are variable according to locality, year of crop production and other factors of influence. Aside from the inhibitory starch-protein relationship, the protein content of the two principal feed grains, corn and grain sorghum, are deficient in both protein quantity (eight to ten percent) and quality. Correction for a deficiency of the essential amino acid lysine, for example, has been attempted by corn plant breeders at considerable expense and effort. It is believed that success has been very modest and certain other desirable factors have been lost in the plant breeding processes. However, such an effort to correct only one deficiency points to the economic importance already placed on improved nutritional value of seeds. The utility of a method to sorb solid and oleaginous nutrients in highly variable amounts and combinations for a multitude of objectives would be immediately obvious to those skilled in the art.
Considering the limitations noted for whole grain accessibility and flexibility required for mixed feed manufacture, a necessary procedure for manufacturing of feedstuffs involves the comminution of grains, as stated above, prior to mixing together all the constituents. Such mixing procedure requires care to ensure uniform distribution of all ingredients, usually numerous, especially the microingredients. A significant portion of mixed feeds, perhaps 65 to 75 percent, are pelleted to prevent ingredient stratification and separation, thus theoretically ensuring a complete feed in each pellet. Also hopefully remedied by such procedure is the tendency of some fed birds to select ingredients from a mash. However, such mixing prior to pelleting seldom results in perfect distribution. Moreover, even optimum distribution, as afforded by conventional mixing equipment, cannot possibly ensure uniform distribution and availability in the context of fine structure availability of the grain particles therein. A significant improvement over the present art, and an obvious expedient, would be a simple, rapid and unusually economic method for encapsulation of those added nutrients in the berry itself to take advantage of the natural "pellet" (cereal kernel) provided, and which would ensure nutrient uniformity and availability and which would preclude possible component separation.
The ability of ruminant animals to utilize non-protein nitrogen (NPN) compounds in place of about one-third of the total protein requirements has been known for about 100 years. Urea, by far is the most commonly used NPN compound used for this purpose, is readily hydrolyzed to ammonia in the rumen, which, in turn, is readily utilized by the operative rumen microflora to multiply, thus producing protein for the fed ruminant animal. The newly generated cells pass from the rumen to subsequent digestive organs where the cells are digested and from which are finally assimilated by the animal. Incentive to use urea as a replacement for protein is high due to the disparity between urea and oilseed prices, with the latter usually costing seven to ten times as much as the former, on a nitrogen basis. Urea and other NPN compound usage have reached very significant levels in spite of the hazards involved, and are expected to reach notably higher levels if attendant problems can be overcome.
To be really effective economically, and to avoid dangers involved, NPN compounds must be administered with the highest uniformity possible. Restrictions inherent in the use of NPN compounds are availability to the fed animal, segregation in mixed animal feed rations, toxicity, palatability, and efficient conversion to protein, all of which are interdependent. Particle segregation occurs due to mixtures of particles which are highly dissimilar in size and shape. Portions of rations are not palatable when containing a high proportion of NPN. Furthermore, once in the rumen, urea is rapidly hydrolyzed to ammonia which may pass through the rumen walls to the animal blood stream. Toxicity results when the bloodstream ammonia concentration exceeds its threshold, which may result in death. Only by exercising considerable care in maintaining uniformity and acceptable availability rate can urea be effectively utilized. To those skilled in the art an obvious improvement over the present art would be the encapsulation and internal sorption of NPN compounds to ensure uniform distribution and which would be available to the fed animal at a rate approximating the availability of the cereal seed tissues.
Processes have been devised for the intimate association of cereal grain component tissues with urea to fashion products which yield about the same total nitrogen content as high-protein oilseed meals. One such process involves the comminution of grain, incorporation of urea and water, then simultaneous heating and extrusion. With total power requirements high, and throughput low, the manufacturing costs have not been satisfactory. Aside from such deficiencies, the effort clearly illustrates the desirable objectives by those individuals associated with the ruminant animal feeding industry. Process heating, however, causes a substantial portion of the urea to be condensed with the starch in the grain tissues, aiding materially in retarding the rate of release of urea, a requirement for a product replacing a protein concentrate. An improvement over the present state of the art would be the sorption or encapsulation of solids in high percentage to form concentrations of NPN compounds, other nutrients, or both, with concurrent retarded rate of availability of such chemicals to parallel the rate of availability of the cereal tissues.
Uniform sorption by the grain of solid chemicals would provide new and novel processes for whole seed utilization in foods, feeds and industrial applications, heretofore unavailable. For example, the placement of enzymes within the whole seed for the purpose of reducing or eliminating interrelated tissue inhibitions, would increase tissue availability. Proteolytic enzymes encapsulated in seed endosperm could be caused to degrade the protein matrix under appropriate superimposed moisture and temperature conditions, all in situ. By reducing the inhibitory starch-protein matrix, the general availability of both tissues would be enhanced to the fed animal or in subsequent procedures for wet or dry tissue separation. Similarly, amylolytic enzymes could be used to "partially digest" starch, an advantage to the fed animal, and especially to the young animal.
A method for uniform encapsulation of reactive chemicals into seed endosperm, which when subjected to superimposed subsequent processes, such as infrared heat or steam under pressure, to produce special products, would have obvious utility. Beans, for example, could be caused to sorb reactive but nutritive chemicals, then caused to react in situ to produce an endosperm with reduced structure. Such legume seeds might be cooked in less time and digested with less stress, an obvious improvement over the present art. A number of other processes, predicated upon seeeds appropriately treated chemically, would be available for the first time. Even such bizarre objectives as negative nutrition, appropriate for the demise of unsuspecting rodents or other damaging vermin, would be practical.
A method for encapsulation of seed dust into the seeds from which it issues would have a huge economic utility. It is well known that the removal of most "foreign matter" from grain is easily accomplished by various means common in the grain industry. However, the smaller the particles, the greater the difficulty in removal and handling. According to most authorities, such as the USDA and universities, the prevailing evidence shows that the fine particles, known as "dust", are usually present in seed commodities in rather small quantities. Wheat, for example, normally contains about 0.05 percent of dust, and up to one percent in extreme and rare cases. It is this fraction, however, which is the really dangerous element regarding explosions, fires, and health hazards (breathing dust and microorganism spores), and this fraction contributes to air polution, grain-weight losses, dust disposal, and other problems. Special utility would issue from a method for encapsulation of such particles in seeds and whose efficiency is in reverse proportion to the particle size, exhibiting extreme efficiency for the most minute particles.